I had a similar problem in a Bonanza (which has bladder tanks). The fuel vent had frozen over and the bladder got sucked up as the tank was emptied. Without considering how much fuel was supposed to be in the tank I switched to it on an approach in a snowstorm (part of the pre-landing checklist was "switch to the fullest tank" and that one read the highest). The engine quit just before I reached the final approach fix. I resolved the crisis by switching to a different tank and the engine started running again but not as fast as my heart was beating.
